Test A was assumed as a perfect gold standard Test B was assumed as a perfect gold standard Test C was assumed as a perfect gold standard Positive results of either test A or B was assumed as a perfect gold standard Positive results of either test A or C was assumed as a perfect gold standard Positive results of either test B or C was assumed as a perfect gold standard Positive results of both test A and B was assumed as a perfect gold standard Positive results of both test A and C was assumed as a perfect gold standard Positive results of both test B and C was assumed as perfect gold standard